Fully telescoped caseless cartridge

ABSTRACT

An ammunition cartridge comprising a projectile which is fully telescoped within a sleeve of gunpowder. At the trailing edge of the projectile, and within the sleeve, a primer cap is positioned for containment of a primer charge which initiates combustion of the gunpowder sleeve. If desired, a casing of any suitable material may be provided for certain applications.

United States Patent Goldin 1 Aug. 29, 1972 [54] FULLY TELESCOPEDCASELESS CARTRIDGE [72] Inventor: Morris Goldin, Orange, Calif.

[73] Assignee: Hughes Tool Co., Aircraft Division, Culver City, Calif.

[22] Filed: Jan. 22, 1970 [21] Appl. No.: 5,031

3,507,219 4/ 1970 Dardick 102/ 38 3,345,945 10/ 1967 Quinlan et al.102/38 3,439,635 4/1969 Hensley 102/ 38 1,659,625 2/1928 Cowan 102/43Primary Examiner-Robert F. Stahl Attorney-Smyth, Roston and Pavitt [57]ABSTRACT An ammunition cartridge comprising a projectile which is fullytelescoped within a sleeve of gunpowder. At the trailing edge of theprojectile, and within the sleeve, a primer cap is positioned forcontainment of a primer charge which initiates combustion of thegunpowder sleeve. If desired, a casing of any suitable material may beprovided for certain applications.

2 Claims, 5 Drawing Figures ester 61. org

FULLY TELESCOPED CASELESS CARTRIDGE BACKGROUND OF THE INVENTION In anysituation in which fire power is required, whether stationary or mobile,such as an airplane, truck, or foot-soldier, the most significantlogistics problem must be considered to be the provision of a maximumamount of ammunition with a given fire power in a minimum volume andwith a minimum weight. Relatively modern weapons employ what has becomeknown as a Standard Brass Cartridge type of ammunition in which aprojectile is mounted at the forward end of a brass casing. A propellantpowder is mounted within the casing and a suitable primer is positionedat the tail end of the casing. Impact of a firing pin or hammer on thecasing in the area of the primer causes ignition and combustion of theprimer and then the gunpowder so that the projectile is driven from theweapon with proper velocity.

More recently, an ammunition has been devised which comprises a tube ofgunpowder into which a projectile is partially telescoped. A primer andprimer cup areinserted in the opposite end of the tube and a largevolume is formed within the tube, between the primer cup and theprojectile, for expansion of the gases from the primer ignition whencombustion begins due to the impact of the firing pin or hammer.

This type of ammunition, sometimes referred to as Frankfort ArsenalCaseless, has resulted in an increased amount of ammunition within agiven volume and weight. Therefore, the Frankfort Arsenal Caselesscartridge can be considered to be a significant improvement upon theStandard Brass Cartridge. However, that is not to say that these ratioshave been optimized to the greatest extent.

SUMMARY OF THE INVENTION The present invention relates to a fullytelescoped caseless cartridge. More specifically, the inventiongenerally comprises an ammunition cartridge in which a tubular gunpowderbody telescopically encases a projectile which is positioned immediatelyadjacent a primer cap in the tail end of the cartridge.

Recent tests have shown that only a very small volume between the primercup and the tail end of the projectile needs to be provided to produce asufificient anvil force on the tail of the projectile to cause it tomove out of the gunpowder tube and through the rifle barrel. Prior tothese tests, it had been thought by those skilled in the art that alarge expansion volume must be provided and the projectile must bepositioned in manufacture to extend beyond the end of the tube in orderto insure that the combustion of the gunpowder tube would take placewholly behind the tail end of the projectile. However, it has now beenfound that the ignition of the primer and combustion of the primer capwill produce a sufficient anvil force to start the projectile moving outof the tube in a sufficient amount of time to insure that the burning ofthe gunpowder tube always takes place behind the tail end of theprojectile.

Thus, the cartridge of the present invention has all of the advantagesfound in the Frankfort Arsenal Caseless cartridge, compared to earliercartridges, while providing the further advantages of significantlyincreasing the number of rounds per unit of volume.

In order to best illustrate the differences between the Standard BrassCartridge (SBC), the Frankfort Arsenal Caseless (FAC) cartridge, and thefully telescoped caseless (FTC) cartridge, and the advantages of thefully telescoped caseless cartridge over the other two, the followingchart is set forth for comparison, for 5 .56 millimeter cartridgeshaving cylindrical configurations, of the weight of the individualcartridges, the number of rounds per 5 pounds for each cartridge, thevolume of each cartridge, and the number of rounds per cubic foot in theoptimum nesting relationship between rounds.

Standard Franldort Fully SBC FAC Brass Arsenal Telescoped vs vsCartridge Caseless Caseless FI'C FTC 5.56 Millimeter (cylindrical)Weight (Grains) 178 91 91 -49% 0 Rounds/5 lbs. 200 384 384 +92% 0 Volume(in.*) .25 .165 .125 50% -24% Rounds/it. 5,979 8,884 1 1,772 +97%Reference to this chart clearly discloses that both the FrankfortArsenal Caseless and fully telescoped caseless cartridge, which weighthe same, produce a significant weight reduction with respect to theStandard Brass Cartridge. Further, it can be seen that the fullytelescoped caseless cartridge can be stored in a far smaller volume thancan the Standard Brass Cartridge or the Frankfort Arsenal Caselesscartridge. In other words, an ammunition box having a given volume ofcartridges formed in accordance with the present invention may weighslightly more than the same box containing the other types of cartridgesbut a far greater number of rounds of ammunition will be containedwithin the box. Thus, the logistical problems involved with supplyingammunition to a gun platform are significantly reduced.

As an additional advantage, with the projectile positioned close to theprimer cup, it can be used as a backup means for the cup, therebyincreasing the strength of the cartridge.

Fully telescoped caseless cartridges also provide a further significantadvantage over all other types of cartridges in that they clearly lendthemselves to being formed in a wide variety of desirableconfigurations. For example, if the external configuration of such acartridge is square, with the same amount of powder and the same sizeprojectile, the number of rounds which can be stored in a given volumeis increased still further. If the external configuration is octagonal,and two opposed sides are of a larger width than the others, therebyforming what shall hereafter be referred to as a flat cartridge, thestorage capacity is not only increased over that of the round cartridgebut the cartridges may also be handled with greater ease.

In order to more clearly illustrate the advantages of such a flatcartridge over the Standard Brass Cartridge and Frankfort ArsenalCaseless cartridge, a second chart is herewith provided which sets fortha comparison of the 0.50 caliber cartridge, according to the presentinvention, with those cartridges.

Standard Frankfort Fully SBC FAC Brass Arsenal Telescoped vs vscartridge caseless Caseless FTC FTC (estimated) .50 Caliber( flat)Weight (Grains) 1788 I400 I400 22% Rounds/ lbs. 14 25 25 +32% 0 Volume(in.*) 2.73 1.98 1.58 42% 20% Rounds/ft. 541 744 1,144 +1 I 1% Thus,cartridges formed according to the present invention have a wide varietyof advantages over prior art cartridges, as well as not requiring caseswhich reveal the presence of a soldier or rifleman when they aredischarged from a rifle, clutter up the usable floor space of anaircraft when fired from a gun mounted in the aircraft, damage theairfoil surfaces of an aircraft when they are discharged from a gunmounted on the outside or nose of the aircraft, and are usable by anenemy in manufacturing boobytraps.

Other advantages, objects, modes, and embodiments of the invention willbecome obvious to those skilled in the art by reference to the DetailedDescription and accompanying drawing which illustrate what are presentlyconsidered to be two preferred embodiments of the best mode contemplatedfor utilizing the novel principles set forth in the claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 comprises perspectiveillustrations of prior art cartridges of the Standard Brass andFrankfort Arsenal Caseless types;

FIG. 2 is an end view of a cylindrical cartridge formed according to thepresent invention;

FIG. 3 is a sectional view of the cartridge of FIG. 2, taken along theline III-III thereof;

FIG. 4 is an end view of a flat round cartridge according to the presentinvention; and

FIG. 5 is a perspective view, partly in section, of the flat roundcartridge shown in FIG. 4.

DETAILED DESCRIPTION The prior art cartridges shown in FIG. I basicallycomprise a Standard Brass Cartridge 11 and a Frankfort ArsenalCaselesstype cartridge 13. The Standard Brass Cartridge generallycomprises a metal casing 15 containing a propellant charge which servesto propel a projectile 17 when a primer, in the area 19 in thecartridge, is ignited by impact with a firing pin or hammer.

The Frankfort Arsenal Caseless cartridge 13 basically comprises atubular sleeve 21 of gunpowder into which a projectile 23 is partiallytelescoped. A primer cup 25 of gunpowder surrounds a primer charge 27which ignites the primer cup and gunpowder tube 21 upon impact with afiring pin. A relatively large volume 29 is formed between the primercup 25 and the tail end of the projectile 23.

Now, with reference to FIGS. 2 and 3, a cylindrical projectile 411 isillustrated in greatly enlarged form, as comprising an outer sleeve 43of gun powder of ball, military, or any other grain configurationdesired. A projectile 45 is fully telescoped within the outer sleeve andmay be either bonded in place by use of a suitable adhesive or held inplace by effectively shrink-fitting the tube onto the projectile. Aprimer cup 47 at the tail end of the cartridge surrounds a primer charge49 which is held within the cup by fish paper 51 in a wellknown manner.A volume 53 of any desired configuration may be formed between the tailend of the projectile 45 and the primer cup. As shown, the volume isconical and allows the gases of combustion of the primer charge and theprimer cup to expand and exert an anvil force on the tail end of theprojectile to move it to the right so that, as the gunpowder tube 43burns, the force generated thereby always acts against the tail end ofthe projectile.

If desired, the volume 53 can be similar in shape to that of volume 29of the prior art projectile but will be much smaller since theprojectile will be positioned closer to the primer cup. In either casethe projectile will be close enough to the cup to act as a back-upmeans, thereby resulting in a stronger cartridge.

The gunpowder sleeves are formed in a variety of ways. For example, aprojectile may be placed within a die and the desired gunpowder placedbetween the projectile and the surface of the die. Any solvent whichwill attack a nitrocellulose may then be injected into the gunpowder tosoften it so that it becomes molded into the desired shape. If thismethod is used, proper solvent selection may cause the gunpowder sleeveto shrink onto the projectile so as to firmly hold it in place. Also, ifdesired, the primer cup 47 can be molded when the tube is molded and theprimer charge 49 may be inserted into the cup at a later time.

Now, with reference to FIGS. 4 and 5, there is shown a cartridge 61having a projectile 63 mounted within an outer sleeve 65. As shown, thecartridge 61 has an octagonal external configuration with a pair ofopposed sides 67 and 69 being of greater dimension than either of theother pairs of sides. Proper formation of ammunition feeding systems andfiring chambers will allow such a cartridge to be easily handled. Infact, if desired, such a cartridge may be moved into the firing chamberin a direction such that the cartridge may be partly injected into thechamber, and therefore under its guiding control, while still beingmoved and controlled by the feed means. Therefore, greater control ofthe cartridge can be exercised in the gunnery system.

Thus, the applicant has described and illustrated two embodiments of anew and improved concept in the ammunition art which yields a trueadvantage in that art. Many further modifications and alterations ofthese embodiments within the scope of the invention will be obvious tothose skilled in the art.

What is claimed as the invention is:

1. In an ammunition cartridge,

a body comprising an explosive charge having a bore therein and apolygonal external periphery so structured as to provide one pair ofopposite sides having a greater dimension than any other pair of sidesthereon, a primer cup in said body adjacent said bore, and a projectilein said bore having a trailing end adjacent said primer cup and aleading end adjacent the other end of said bore and within said bore. 2.An ammunition cartridge comprising a sleeve member formed of anexplosive charge having an octagonal polygonal external periphery havanopposed pair of equal width sides having a greater width than either ofthe other pairs of sides,

a bore extending through said sleeve member, a primer cup at a first endof said bore, and 5 a projectile entirely within said bore and having aleading end adjacent the second end of said bore.

1. In an ammunition cartridge, a body comprising an explosive chargehaving a bore therein and a polygonal external periphery so structuredas to provide one pair of opposite sides having a greater dimension thanany other pair of sides thereon, a primer cup in said body adjacent saidbore, and a projectile in said bore having a trailing end adjacent saidprimer cup and a leading end adjacent the other end of said bore andwithin said bore.
 2. An ammunition cartridge comprising a sleeve memberformed of an explosive charge having an octagonal polygonal externalperiphery having an opposed pair of equal width sides having a greaterwidth than either of the other pairs of sides, a bore extending throughsaid sleeve member, a primer cup at a first end of said bore, and aprojectile entirely within said bore and having a leading end adjacentthe second end of said bore.